Nonmetal Mineral : Belonging to the class of inorganic structural and industrial minerals that do not become metals through metallurgical refining, such as potash, asbestos, sulfur, granite, and rock aggregates
NFPA 122 Standard for Fire Prevention and Control in Metal/ Nonmetal Mining and Metal Mineral Processing Facilities, 2004 ed. http://catalog.nfpa.org/NFPA-122-Standard-for-Fire -Prevention-and-Control-in-MetalNonmetal-Mining-an d-Metal-Mineral-Processing-Facilities-Prior-Years- P4168.aspx, (Std: FrPrev and Cont in Metal/ Nonmetal Mining and Metal Mineral Procss Fcilty - Amer) {254 NFC}